A physical unclonable function (PUF) is a process usable to create a unique, random key for a physical entity such as an integrated circuit or a semiconductor memory device. Use of a PUF is a solution for generating chip IDs (Identity) supporting a hardware intrinsic security (HIS) technology on a physical entity such as an integrated circuit or a semiconductor memory device wherein each chip is related to its own chip ID. In order to achieve low bit error rate and high uniqueness, PUFs have been used for key creation in applications with high security requirements, such as mobile and embedded devices.
Most PUF may generate chip ID based on threshold voltage differences in the transistors, for example, the SRAM PUF or the floating-gate memory PUF. ReRAM (Resistive random-access memory) PUF has been developed which use resistance difference to generate chip ID. However, in high temperature, most PUF still has high bit error rate.
It is desirable to provide a semiconductor memory device, a chip ID generation method and a manufacturing method therefor, which may improve randomness of PUF and may efficiently decrease bit error rate even in high temperature.